My in-laws moved from Illinois to California 3 years ago. They moved to an area about 1.5 hrs NE of San Fancisco (Antioch/Pittsburgh/Brentwood). They are older, but have made many friends through their church and from work. They LOVE the weather there! Their winters are in the 50s and rainy, but nothing compared to MN winters. It is not nearly as metropolitan as the Twin Cities (my hometown), but it is big enough to not feel isolated, and then San Francisco is not too far away.
Downsides to that area of California - the state is broke and is definitely going to be raising taxes
- area is prone to minor earthquakes, but has the potential for a more major one
The housing market is still unstable, but the property values have sharply declined in that area, so you can get a pretty nice newer construction home there for around $300-350k (not bad for Cali prices.)
Their biggest regret is banking on the idea that WE'D want to come to Cali too--they thought they could lure us there, but I have no intention of moving even further away from my own family than I already have.
If WE ever move to a warm weather destination, it'll be the Jacksonville, FL area. We have some family there, the housing is cheap, and the area is poised for some major growth, thanks to the construction of a new port that will be bringing thousands of jobs to the area.